Response Time

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Response Time

• Transportation Ch. 1, Act. 1

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What do you think?

• How fast do you think you would be able to
  respond to an emergency situation on the road?
• The average response time for most drivers is
  about 0.33s.

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What do you think?

• How far can you go in 0.33s?
• At 30 mph, this is 14 feet.
• At 60 mph, this is __ feet.
• This is BEFORE you try to stop the car.

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(No Transcript)
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Response Time

• What factors affect response time?
• Alertness
• Drugs alcohol
• Age
• Distractions
• Conversations (cell phone and others)
• Eating drinking
• Putting on make-up
• Rubber necking

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Highway Statistics 15-20

• 2004
• 24 percent of fatally injured drivers aged 15-20
  were intoxicated (blood alcohol concentration
  BAC greater than 0.08 percent).
• 2003
• 6.3 percent of licensed drivers,
• 13.6 percent of all highway fatal crashes. 

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Highway Statistics 15-20

• 2002
• Crash severity increases with alcohol
  involvement.
• 2 percent of drivers in property-damage-only
  crashes had been drinking.
• 4 percent of young drivers in injury crashes had
  been drinking.
• 23 percent of young drivers in fatal crashes had
  been drinking.
• 40.8 billion estimated cost of
  police-reported young driver crashes.

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Highway Statistics 15-20

• Young drivers do only 20 percent of their driving
  at night, but over half the crash fatalities of
  adolescent drivers occur during nighttime hours.
• The risk of a crash involving a teenage driver
  increases with each additional teen passenger in
  the vehicle.

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Highway Statistics 15-20

• Research shows that the cognitive effects of
  conducting a conversation on a wireless telephone
  can decrease situational awareness and that
  wireless telephone use can increase reaction
  time.
• A 2001 study, "Driver Situational Awareness and
  Carphone Use," reported that drivers engaged in
  wireless conversations were unaware of traffic
  movements around them.

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Average vs. Instantaneous Speed?

• Average Speed Total distance traveled / total
  time.
• Average speed is independent of the path
  traveled. It does not necessarily reflect your
  speed at a given moment in time.
• Instantaneous Speed The speed that you are
  traveling at at a specific moment in time.

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Observing Speed

• Speed can be observed and represented in a couple
  of ways.
• Motion Diagrams A strobe representation through
  pictures of a moving object taken at a specific
  time interval.
• Graphs Speed can be determined through
  graphical analysis where the distance or velocity
  of an object may be measured vs. time.

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Motion Diagrams
Constant Speed
Positive Acceleration
Negative Acceleration
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Graphical Anaysis
Distance or Velocity
Time